import os
import sys

# 请在此输入您的代码

import datetime

start = datetime.date(2000,1,1)
end = datetime.date(2020,10,2)

res = 0
while start < end:
  if start.day == 1 or start.weekday() ==0:
    res += 2
  else:
    res += 1
  start += datetime.timedelta(days=1)

print(res)
